Circuit breaker control



Jan. 19, 1937. G N. LEMMQN CEERLCUIT BREAKER CONTROL v Filed July 15, 1933 2 sne'etg-snm 1 Jan. 19, 1937. G N. LEMMON 2,068,$21

I cmcurr BREAKER CONTROL Filed July 15, 1933 2 Sheets-Sheet 2 INVENTOR oil -circuitbreakers or Patented Jan. 19, 1937 UNITED STATES PATENT OFF-ICE Southern State Equipment Company, Birmingham, Ala'., a corporation Application my 15. 1933, Serial No. 030.593

' k 15 Claims. 10!. 175-294) One of the objects of my invention is to provide a simple and reliable means to operate acircuit breaker located in a main line at a remote distance from the power supply, without the need of a separate control or pilot circuit. The circuit breaker may either be of the type known as of the type known as airbreak switches.

A, further object is to provide equipment to control a circuit breaker located in a main line at a distance from the power supply breaker, such control equipment acting automatically to open, reclose, re-open and lock-out the said line circuit breaker as required, only by the conditions of flow in the said main line.

It is known that this general plan has been previously used by others, but it is believed that the method now disclosed is entirely new and original.

and being regulated voltage and current- The desired objects are accomplished by employing an arrangement of relays which respond only to a pre-determined series of varied condi-" tionsin-the main-line, and when so responding the relays act to operate the breaker, as desired.

A selected series of varied conditions in the main line can be produced station breaker through which power is supplied to the main line. A difierent series of conditions may be produced by including also the eiiect of overload in the lineas one of the items) in the series. 1

Referring to the drawings Fig. 1 is a diagram of one arrangement of circuit breakers, relays and auxiliaries, which employs my invention; and Figs. 2Tind 3 are diagrams of some of the relays used, as will be explained later. i

In Fig. 1, the line circuit breaker or switch I can be closed by means of the insulated member 2 against the'action of the opening spring "3. A motor! drives the cam 5 and the cam-switch 3 counter-clockwise and at a speed which we may select as one revolution in 10 seconds. A bar I is pivoted at 3 and'rests on the cam 5 so'that the bar rises and falls as the cam 5 revolves. A hook 3engages with a hook I in the lower end of 2 when the bar 1 is fully raised, and a compression spring I l is strong enough to force 1 down against 1 the resistance oi the breaker I and the spring 3 when 3 and ID are engaged. This closes the breaker I as the cam is revolved to the position shown injlg. 1.

A solenoid I2, when energized, disengages 3 from' III, whereupon the spring 3 'acts to. open I again. Auxiliary contacts I3 and I4 are automatically closed when I is open, and contacts l5 are closedwhenJ is closed. A lockout coil I3, when 'energized, 'acts to open the contacts I1 and to close the contacts I3. The device is arranged so that these contacts will so minim untirtheopening the contacts I3 and closing by opening and closing the push button I3 is used to re-set the lookout by I1. A bat. tery 23 and a potential transformer 2I furnish power at suitable voltages to operate the motor 4 and also the various relays and control switches.

The relays 22, 23, 24 and 25 are the special ones upon-which my invention depends. Fig. 2 shows relay 22 in diagram. A mercury-switch 26 is secured to a base 21 which is movableabout the pivot 23. When 21 is rotated by the upward pull of the solenoid 23 until the arm 21' touches the stop 33, then the mercury 3| closes the contact between 32 and 33. When the base 21 is rotated by gravity until 21' is held by the stop. 34, then the circuit 32-43 is open and 32-42 is closed. Attached to the end of 21 by two pivoted toggles 33 and 36 is a toothed'segment 31 which engages with the pinion or the gear 33. The gear 33 in turn engages with the pinion of the inertia wheel 33. A stop 40 limits the travel of 36, and a suitable spring, not shown, tends to keep against 21 as shown. It is evident that when 23 is energized 21 1lbe instantly lifted to its highest position, for

acts like a ratchet and slips past the teeth in-the pinion of 33. But when 23 is deepergized and 21 drops downward then 31 engages i'ully'with the pinion of 33, and the descent of de-energized for a predetermined interval. In

the arrangement shown I select 2 seconds as this interval; but some other interval might be chosen as well, and the relay be adjusted accordingly.

" Fig. 3 shows a relay which has a delayed ac-,

tion of 5 seconds in each direction. The mercury-switch has 3 contacts-43, 41, 53; and the base 4| engages-continually with the pinion of the gear 42, which in turn revolves the pinion and the induction disc 43. This disc is'between the poles 44' oi. the damped electro-magnet 44,

and when 44 is energized the disc 43 is slowly revolved just as "is the disc of the standard induction .watt-hour meter.

. As 43 is revolved counter-clockwise by 44, the base is slowly raised until the arm 4| reaches the stop 45. The contacts 48-41 are then closed by the mercury which is inside the mercury switch. when u is'de-nergizedythe weight of the base H and its attached partstends to revolve it about the-pivot 48, and the disc 43 acts as an inertia wheel and delays this motion. When 4b is against the stop 43, the contacts 43-41 ayeopen and the contacts 41-453 are closed by the mercury. The parts are so proportiond that the desired 5-second interval is obtained in both motions of therelay. It will be noted that in Fig. 1 the'diagram shows 23 as a 4-point relay, but'the terminals are actually shown in Fig. 3, and time a only one contact terminal 41.

Relay 2 is similar to Fig. 2 except that the contacts 31-42 are the ones used, and the parts ll, SI, 81, a, ll and II are omitted. In Fig. 1 the contact 32'. designates the contact shown as 82 in Fig. 2. This relay givesan'instantaneous action, with the relay contacts open when the coil is energized. If desired, an instantaneous relay of another design may be used at N.

Relay 2! is similar to'l 'ig. 8, with contact 50 not used, and the other contacts designated in Pig. 1 as w-u'.

The wiring diagram of one arrangement is shown in Fig. 1, and the chosen operating schedule required by this arrangement is as described in operations A, B, and C.'

Operation A, to open I temporarily. Have power of! the main line for seconds or more,

then put power on and take it 03 again within 2 seconds. This will-open I.

Operation 3, to close I. Apply power to the main line for 15 seconds. This will make I close. Operation C to open I and lock it open. Have I open, put power on the line ior15 seconds. This will close I, as in operation B. Then withi 2 seconds-from the time I has closed take powei' oi! the line, and I will automatically open and lock itself out.

The different conditions named above seldom occur 'in the serial orders as given, under normal operation conditions. And so line switches fitted with this equipment are not apt to be op-.

erated accidentlyn In case of serious trouble on the line, however, the named conditions are apt to occur and then the line switches will automatically act to open themselves and clear the trouble.

Details are as follows:

Operation A.--I.et it be assumed that the source of power is a generating station at the left, that the switch I is closed and that power flows through the line as indicated by the arrows to a load at the right. Under normal conditions power will be on the line, 9 engaged with III, I held closed, contacts II closed, contacts i1 closed, coils of relays 23 and N ,energized, contacts "-41 closed and all other relay contacts open. When power goes oi! the line, as by the opening of the breaker I' at the generator station, II is tie-energized and therefore so are the coils-oi relays II and u. If power comes back in less than Erseconds no change occurs. If power stays oi! for over 5 seconds contacts "-41 are opened and contacts 41- 5. are closed. .When power comes back,,whether in seconds or two hours, the coils of, 28 and 1.4 are energized, thereby closing 33-" and opening the contacts oi re lay it at lT-ll"- ,1! power stays on for 5 seconds, contacts 41-" are opened, 22 is de-energized, and normal conditions are resumed. However, it power goes of! within two ,seconds from the time 22 has been energized, then It is de-energized and closes its contacts at "'42" while 38-42 are still closed,'

and the circuit is thereby closed from the battery 2| through I, 82, 32"32, I5, the trip coil I2, 88, 38-41, and so back to the otherpole of the battery. Thus the coil ll is energized, 8 Is thereby disengaged from I0, and the spring I opens the line switch I. This closes It and I4, and also opens II.

, Temporary line trouble, such as a momentary flashover, due tolightning, will cause the circuitbreaker at the generating station to open. There 'case the line trouble was only temporary, the

overload will not'be repeated at once, and the breaker will stay closed, thereby keeping the line energized and resuming service through the switch I to the load beyond I, and in 5 seconds all relays have assumed normal position. This is normal operation, and despite the overload which opened the breaker at the generating station, the line switch I remains closed, because the contacts 33-42 and il -3'1" are not both closed at the same time, under these conditions.

' On the other hand, if the line trouble is permanent, then when the station breaker is reclosed it will at once open again, thereby producing the conditions described under operation A and so causing the line switch I to open.

Operation B.-When, power comes back on the line,the coil of 23 is energized and after 5' seconds "-41 are closed, and the circuit is closed from the battery through llI1', the motor 4, ll, 48-41, 55 and so to the battery negative. The motor 4 therefore starts to turn,-

6 closes its contact and makes direct circuit back to the battery negative. Therefore the motor completes its cycle; the cam lifts 1 until 9 engages with II); and, as the cam 5 continues to turn, the spring II forces I down and so closes I. Meanwhile the motor circuit is opened simultaneously at It and at 8.

Operation C.- While I is open the contacts I! are closed and so with power on the line 2| is energized, and the coil of 25 is energized, closing the contacts 'l1' after 5 seconds. As soon as I closes as in operation B, contacts I! are also closed, and if power goes on again within 5 seconds from the closing oi I, thecoil oi 2| is de-energized and the contacts l2"-32 are closed.

Thus the circuit is completed from the battery through 5|, 52, 32"-l2', I I, I, the lookout 0611 I6, 8'41, 55, and so to the battery negative.

This operates the lookout coil II and opens the motor circuit at I1 so that reclosure is impossible; it also closes the contact II thus completing the circuit from the battery through Ill, 52, I2" I2', I5, the trip coil I2, II, to the battery negative. This operates the trip coil I! and opens the switch I, leaving it locked out until reset manually by I.

It may sometimes happen that a short circuit occurs on the line so close to the switch I that suiilcient voltage cannot be built-up on the line to energize properly the potential transformer 2|. Under such conditions there would be excessive amperage in the line, and the desired results are then obtained by combining a current relay with the voltage relays and other devices. The current transformer 59 is connected directly to'the relay '51, and upon excess overload the contacts 5! are thereby closed instantaneously. When power goes oil, the contacts ll open with a 2 second delay. Operation is as iollows:

Operation D.-When power has been oi the line for 5 seconds or more, with the switch I closed, and an excess overload suddenly comes on the line accompanied, or immediately-followed,

.by a condition 0! no-voltage, then the switch I 'tacts 32"42' will not open until II is properly energized. Therefore, it an excess load is imposed on the line under'such conditions that voltage does not build up, the relay I1 closes the contacts 58 and the tripping circuit is completed from the battery, through 54, 52, the contacts IZ"I 2', the switch It, the trip coil 12, 60, contacts 5|, 6| contacts 50-41 and 5! to the other side of the battery.

Ii voltage has been suillcient to operate the relay 24, then 32"-32' will open momentarily, but will close again as soon as power goes oil the line due to opening the circuit breaker at the generating station. In each of the various operations described above several successive steps are necessary; and it is obvious that if any one of these steps does not occur, then the resultant operation will not occur. In such case the relays tend to return to normal conditions.

One of the new features of. my invention is the use of two or more relays having diflerentperiods of operation and different connections, but with their contacts in series, whereby a continuous momentary cifcuit through the relay contacts is completed ii, and only in case, the correlated apparatus has just passed through a definite series of motions or changes within a predetermined time. This plan-avoids the need for any motor driven timing devices which have to be closely coordinated with other similar equipment connected with the distant breaker at the source of power. Y I

My relays have all the advantages oi! mercuryto-mercury contact and they also employ a design that readily gives a delay of several seconds. Coordination between diilerent relays is thereby secured easily. With these relays, also, there is no problem of resetting them to normal position,

since each relay always returns independentlyto its own normal position after a few. seconds. The relays. are readily arranged to give any desired time delay on either the opening or closing motions, and upon either the energizing or deenergizing of the coils.

Only a few series of actuating conditions have been described. It is obvious that many other modifications and changes in the schedule of conditions can be made without departing from the principles of my invention. It is also obvious that these principles of circuit breaker control can be usedfor a wide variety of sides those here described in detail.

It is also obvious that this complete control consists of various interconnected relays which act in different groupings under different imposed conditions. Under one given set of conditions, the relays automatically form themselves into a group which acts in one pre-determined way. Under other conditions, the relays form into a difierent group, and this group acts in a diil'erent way from the first group. It-is also obviousthat it it is desired to obtain only the action which is produced by one group of the relays under one set of conditions, then it is onlynecessary to omit the relays which are not a portal? the desired group. Such omission will not aiifect the operation of the relays whichare retained and such changes do not depart from the spirit and purpose or this invention. The invention includes each of the separate operations described, as well as the complete interconnected system which purposes beproperly meets whatever abnormal condition may be imposed upon it.

I claim:

1. A system of electrical circuit breaker control which comprises a source of supply, a main clr-' 5 cuit for the distribution of power, a main circuitbreaker connected to the source and controlling the flow of current from the source to the main circuit, a line circuit-breaker in the main circuit and remote from the said main circuit-breaker, and automatic control equipment which includes devices which are operable to cause a primary opening of the line circuit-breaker if and only when the main circuithas remained de-energized for at least a predetermined time, and then been re-energized momentarily and then been deenergized again, all within a predetermined. interval.

2. A system of electrical circuit breaker control which comprises a source of supply; a main circuit for the distribution of power, a main circuitbreaker connected to the source and controlling the flow oi currentjrornthe source to the main circuit, a line circuit-breaker in the main circuit and remote from the said main circuit-breaker, and automatic controlequipment located adjacent to the line circuit-breaker and operable to cause a'primary opening of the line circuit-breaker ii and only when the main circuit has remained de-energized for at least a predetermined time, and then been re-energized momentarily and then been de-energized again, all within a predetermined interval.

3. A system oi electrical circuit breaker control which comprises a source of supply, a main circuit for the distribution, of power, a main circuit breaker connected to the source and controlling the flow of power from the source to the main circuit, a line circuit breaker in the main circuit and remote from the said main circuit breaker, and automatic control equipment which includes devices which are operable to cause a primary opening of the line circuit breaker ii and only when the main circuit has remained de-energized for at least a predetermined time, and then been re-energized momentarily and then ,been deenergized again, all within a predetermined interval,'and which also includes devices which are then operable to close the line circuit breaker when it has been energized at one side for a pre- 50 determined time, and also operable to reopen and keep it open if it is de-energized immediatel after having been thus closed. 4. A system of electrical control which includes a main circuit and a circuit breaker con- 55 nected thereto, elcctro-mechanical closing means to close the breaker and an electro-mechanical lockout device operable to render the said closing means inoperative, a relay which is operable when energized by power from the main circuit to close the operating circuit of the lockout d vice, and which is operable to open the said circ t of the lockout device with a predetermined time delay after the relay has been die-energized.

5. A systemoi' electrical control which includes a main circuit and a 'circuit breaker connected thereto, electro-mechanical closing means to close the breaker and an electro-mechanical lockout device operable to render the said closingmeans inoperative, a" relay which is operable when energized by power i'rom the main circuit to close the operating circuit of the lockout device, and which is operable to open the said circuit 01' the lockout device with a predetermined time delay after the-relay has been .de-energized, a second able in'series with the contacts of the second relay to close the said circuit of the lockout device when the breaker is closed. V

6. A system of electrical control which includes a main circuit and a circuit breaker connected thereto, electro-mechanical means operable to open the breaker when an auxiliary circuit is energized, and relay equipment which is operable when energized by power from the main circuit to open the said auxiliary circuit with a predetermined time delay after the relay equipment has been so energized.

7. A system of electrical circuit-breaker control which comprises a source of supply, a main circuit for the distribution of power, a main circuit-breaker connected to the source and controlling the flow of power from the source to the main circuit, a line circuit-breaker in the main circuit with automatic control equipment located adjacent to it, and containing devices which are operable to cause a primary opening of the line circuit-breaker under overload conditions in case, and only in case, the said main circuit shall have remained de-energized ior at least a predetermined interval just prior to the occurrence of said overload conditions.

a. A system oi'electrical circuit breaker control which comprises a sourceoi supply, a main circuit for the distribution or power, a main circuit breaker connected to theme and controlling the flow oi power from the source of the main circuit, a line circuit breaker in the main circuit and remote from the said main circuit breaker, and automatic control equipment which includes devices'which are operable to cause a primary opening of the line circuit breaker it and only when the main circuit has remained de-energised for at least a predetermined time and then been reenergised momentarily and then been de-energised again aliwithin apredetermined interval, and also operable to close thelinecircuitbreaker whenithasbeenopen and has been energised at oneside for a predeterminedtime interval.

0.1 system 0! electrical circuit breaker control which comprises a sourceot supply, a main circuit tor the distribution of power, a main circuitbreakerconnectedtothesourceandcontrollingtheilowctpowertromthemrcetothe maincircuiflalinecirouitbreakerinthemain circuit and remote from the said main circuit breaker; and control equipment which includes dsvicathatare'locatedadlacenttothe line circuit breaker and are operable automatically to cloaetbelineeircmtbreaker'whenithaabeen open and enerailed at one side for at least a predetermined time; and also operable to prevent subsequent automatic reclosina'in case, and

onlyineaae,themaineirc\iitbecomeade-enerream a breaker control as described in claim 8 and operable to be opened and closed as there described, and also operable to return to normal conditions in case the linecircuit breaker shall remain energized for a predetermined time interval after being so opened and closed. I

11. A system of electrical circuit breaker control which comprises a source 01' supply, a main circuit for the distribution of power, a main circuit breaker connected to the source and controlling the flow oi power from the source to the main circuit, a line circuit breaker connected to the main circuit and remote from the said main circuit breaker, and automatic control equipment which includes devices which are operable to cause a primary opening of the line circuit break er it and only when the main circuit has remained de-energiz'ed for at least a predetermined time, and then been re-energized and overloaded, and then been de-enrgized again, all within a we determined interval.

12. In combination, a circuit breaker and control equipment which includes three relays operable in coordination to cause an opening oi the circuit breaker, one of said relays closing its contacts when de-ehergized and keeping themclosed for-a given interval after being re-energized, a second of said relays closing its contacts instantly when energized and keeping them closed ior a given interval after being de-energized, and the third of said relaysopening its contacts instantly when energized and closing its contacts instantly when de-energized.

13. In combination, a circuit breaker and control equipment which includes three relays operable in coordination to cause an opening oi! the circuit breaker, instantly when energized, one of said relays closing its contacts when deenergized and keeping them closed for a given interval after being re-energised, a second of said relays closing its contacts upon occurrence of overload through the circuit breaker, and the third relay closing its contacts when de-energiaed.

14. A system of electrical circuit breaker control which comprises a source oi supply, a main circuit for the distribution of power, a main circuit breaker connected to the source and controlling the iiow 0! power from the source to the main circuit, a line circuit breaker in the main circuit and remote from the said main circuit. and automatic control equipment which includes devices which are operable to cause a primary opening of the line circuit breaker it and only when the main-circuit has remained de-energimed 101' at least a predetermined time and then been re-energised and overloaded and then been deenergised again all within a predetermined interval, and also operable to close the line circuit breaker when it has been open and has been energised at one side for a predetermined time interval. 1 q

15. A system 0! electrical circuit breaker con 'trol as described in claim 14 and operable to open and close the line circuitlbreaker as there described, and also operable to return to normal conditions in'case the line circuit breaker shall remain energised for a predetermined time interval after beine :0 op ned and closed.

7 GEORGE N. LEIDION. 

